//+ 仅选择JavaScript
var js = $("#para-1");
console.log(js);

//+ 仅选择Erlang
var Erlang = $("[class='color-red color-green']")
console.log(Erlang);

//+ 选择JavaScript和Erlang
var JE = $(".color-red");
console.log(JE);

///+ 选择所有编程语言
var sum = $("p.color-green,p.color-red,p.color-black");
console.log(sum);


// + 选择名字input
var nameInput = $("input[name=name]");
console.log(nameInput);

// + 选择邮件和名字input
var emailName = $("input[name=name],input[name=email]");
console.log(emailName);

//DOM和JQuery对象转换
var DOM =emailName.get();//JQuery对象转换成DOM对象
console.log(DOM);
var hhh= $(DOM)//DOM对象转换成JQuery对象
console.log(hhh);